The invention relates to a rotating joint--a knuckle joint--for a profiled crossbeam with inner cable duct. The joint consists of an upper part and a lower part, which are screwed together and have mounting flanges on opposite front faces.
Rotating joints of this type are used to link frames for constructing office furniture such as desks, conference tables, etc. The frames in this case accommodate brackets to which tabletops are attached by means of a support frame for the top. It is possible to create a plurality of desk configurations and conference table configurations by linking the frames with the aid of the rotating joints and subsequently mounting the adapted tabletops.
The frames consist of vertical supports with skids at the ends facing the ground and are designed to provide a high stability. At the ends facing away from the ground, the supports are screwed to the horizontally arranged profiled crossbeams. The profiled crossbeams have an open cable duct on the side facing away from the ground, which is used to run the electrical lines for lighting and computers, as well as the telephone lines. Once the tables are assembled, the cables inside the ducts are not visible because the tabletops are arranged on the profiled crossbeams. The use of profiled crossbeams with different lengths makes it possible to create optional size tables. The rotating joints, which are arranged between the front faces of neighboring profiled crossbeams, if necessary, permit the adjustment of angles between the profiled crossbeams, thus making it possible to create asymmetrical configurations that deviate from the linear linking.
Known rotating joints have at least one screw in the center region around the rotational center of the joint. As a result of the central screw connection, the free passage through the cable duct is no longer ensured. If the cable duct holds several lines, in particular, this leads to a bunching up of lines in the central rotating range because of the screw arranged therein. In the extreme case, this can result in damage to the lines.